Electrical plug socket



June 19, 1934. R. s K L ET AL 1,963,061

ELECTRI CAL PLUG SOCKET Fil ed Feb. 21, 1929 fia/z 5 era/7.5

I N V EN TORS A TTORNEY.

.Fe 1e. 19

T TATES 1,963,061 sLEcTmcaL PLUG socxs'r Richard S. Bicknell, Red Bank, and Frank J.

Stevens, Nutlcy,

N. 1., assignors to Isolantitc,

Inc., a corporation of Delaware Application February 21, 1929, Serial No. 341,622

3 Claims.

The present invention relates to electrical plug ockets, and while this invention may be applied to various types or electrical attachment receptscles, it is particularly adapted for use in sockets tor tub-es used for radio and the like.

In accordance with this invention, we form a blocs. of insulating material, such as porcelain or a resinous molded composition, in which are the holes for the electrical contact prongs or the member to be connected, such as a radio tube. These holes, which extend through the block, are formed at the top of appropriate sizes to receive the contact prongs, but are enlarged for a substantial distance up from the bottom. Near the top of the enlargement, notches are formed in the sides of the holes. Such notches would be very dimcult to mold, or out directly in the insulating material, but we have found that they can be made very inexpensively by forming transverse holes through the block intersecting the prong-deceiving holes. For a socket to be used tor an ordinary Iour=clement radio tube, only two such transverse holes need to be provided,

' as each of theznwill form the notches in the sides of two of the prong receiving holes.

A contact member is'provided for each of the holes intended to receive a contact prong. .Phese contact members are preferably made from a single piece of resilient material such as bronze, and are shaped to provide side portions which will lie adjacent the sides of the prong holes, which portions are provided with lugs adapted to enter the notches. The side members should be so shaped that when the prongs are inserted in the socket, these side :cem ers will be put under tension to force their top portions toward the sides oi the hole to lock the lugs in place in the notches and at the same insure good electrical contact with the prongs inserted. An extension is preferably formed integral with the side members to which 1?. wire may be attached.

. Gut: invention can readily be understood from ac ompanylng drawing, in which, for the poses of illustration, we show our invention enr ched to a socket for a radio tube. In the Fig. 1 is a perspective view of the socket completely assembled; Fig. 2 is a section on line t2--2 of Fig. 1; Fig. 3 is a section on of Fig. l and Figs. 4 and 5 are perspective views showing two forms of contact member that may be used.

he clock 10, which is made of insulating maat such as a ceramic product, is provided with a prong receiving holes 12. Two holes 14 extend transversely through the block and each of the holes 14 intersects two of the holes 12. The block here shown is cut away at the corhers and provided with holes 16 to receive screws or bolts to attach the socket to the base of the radio set.

As shown in Figs. 2 and 3, each of the holes 12 is enlarged for a substantial distance up from the bottom, such enlargement extending upat least as far as the intersection with the holes 14, .5 so that the holes 14 form notches in the sides of the enlarged portions of holes 12. v

The form or contact member shown in Fig. 4 has two side portions 18 which are preferably curved about the vertical axis and are also pret- 7 erably bowed in toward this axis to provide good electrical contact with the prongs of the tube base. Each of the portions 18 is provided with a lug 20.- The two portions 18 are formed integral with an extension 22, which will ordinarily be tinned for ready soldering to a lead wire. This contact member should be made of resilient material such as bronze. To assemble the contact members in the socket, the sides 18 are pinched together and then inserted from the bottom in a hole 12 with the lugs 20 uppermost. Such member is pushed in as far as it will go and then (if necessary) turned until the lugs 20 snap into the well-like openings formed by one of the holes 14, making a very strong assemblywithout the use of any screws, bolts or rivets.

As shown in Fig. 2, when a tube is inserted in the base, the prongs will enter freely between the lugs 20 and then, as the tube is pushed further in, will contact with the bowed-in sides of portions 18, but before any pressure is developed, tending to dislodge the contact member, lugs 20 will be locked in the notches of the sides and thus disengagement of these lugs will be impossible. When the tube is all the way in, the sides will be under tension to hold the lugs in place and provide good electrical contact.

A slightly different form of contact member is shown in Fig. 4, in which two bowed contact portions 24 are provided, in addition to the portions 18' which carry the lugs 20'. It may be noted that the attachment extension 22 is here shown as not perpendicular to the plane through the centers of the lugs 20'. Various other forms of contact member can readily be designed which will snap into place in the notches formed in the sides of the holes 12 and be held locked in such holes by the prongs of the radio tube.

It is to be understood that the example given and that our invention maybe applied to other types of plug sockets such as base-board sockets,

' ,or attachment sockets for the separable type attachment plugs used on various articles of electrical equipment such as percolators, flat-irons and the like.

What we claim is:

1. An electrical plug socket of the type described comprising a socket of insulating material, said socket being provided with holes adapted to receive resilient metal contact members and being further provided with small transverse passages drilled through said socket intersecting at right angles the metal contact member holes, so as to form recesses therein, resilient metal contact members, adapted to spread-apart, and lugs positioned upon said contact members adapted to engage said recesses so as to position the metal contact members.

2. An electrical plug socket comprising a plug of insulating material, contact prong holes in said plug, notches in said holes formed inga well shape by small holes transverse to said prong holes, resilient U-shaped contact members in said prong holes which substantially fill said holes, and lugs extending into and substantially filling said notches mounted upon the ends of the U-shaped members and having free ends normally extending outwardly further than the width of said prong holes so that the lugs, when the resilient members are inserted into the prong holes, snap into said notches and hold the members free from substantial horizontal or vertical movement.

3. A structure as specified in claim 2, in which said resilient contact members in said holes are of a generally U-shape, but with the U appreciably narrowed near the top thereof and then flared outwardly and in which said lugs are mounted at the ends of the U and extend outwardly into said notches to lock the members in position against any substantial horizontal or vertical movement whereby when prongs are inserted said prongs are led by the flaring U-top to the narrowed portion of the U-shape members and expand the resilient members so that said lugs are driven further into said notches to increase the locking action of said lugs.

RICHARD S. BICKNELL. FRANK J. STEVENS. 

